user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/sysdeps/astral/threading/x86_64-thread-entry.S

@@ -0,0 +1,8 @@
+ .section .text
+.global __mlibc_thread_entry
+__mlibc_thread_entry:
+	pop %rdi
+	pop %rsi
+	pop %rdx
+	call __mlibc_thread_trampoline
+.section .note.GNU-stack,"",%progbits

user/include/mlibc/sysdeps/astral/threading/x86_64-thread.cpp

@@ -0,0 +1,55 @@
+#include <sys/mman.h>
+#include <mlibc/debug.hpp>
+#include <errno.h>
+#include <mlibc/all-sysdeps.hpp>
+#include <bits/ensure.h>
+#include <mlibc/tcb.hpp>
+
+extern "C" void __mlibc_thread_trampoline(void *(*fn)(void *), Tcb *tcb, void *arg) {
+	if(mlibc::sys_tcb_set(tcb))
+		__ensure(!"failed to set tcb for new thread");
+
+	while(__atomic_load_n(&tcb->tid, __ATOMIC_RELAXED) == 0)
+		mlibc::sys_futex_wait(&tcb->tid, 0, nullptr);
+
+	tcb->invokeThreadFunc(reinterpret_cast<void *>(fn), arg);
+
+	__atomic_store_n(&tcb->didExit, 1, __ATOMIC_RELEASE);
+	mlibc::sys_futex_wake(&tcb->didExit);
+
+	mlibc::sys_thread_exit();
+}
+
+#define DEFAULT_STACK 0x400000
+
+namespace mlibc {
+	int sys_prepare_stack(void **stack, void *entry, void *arg, void *tcb, size_t *stack_size, size_t *guard_size, void **stack_base) {
+		// TODO guard
+
+		mlibc::infoLogger() << "mlibc: sys_prepare_stack() does not setup a guard!" << frg::endlog;
+
+		*guard_size = 0;
+
+		*stack_size = *stack_size ? *stack_size : DEFAULT_STACK;
+
+		if(!*stack) {
+			*stack_base = mmap(NULL, *stack_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+			if(*stack_base == MAP_FAILED)
+				return errno;
+		} else {
+			*stack_base = *stack;
+		}
+		
+		*stack = (void *)((char *)*stack_base + *stack_size);
+
+		void **stack_it = (void **)*stack;
+
+		*--stack_it = arg;
+		*--stack_it = tcb;
+		*--stack_it = entry;
+
+		*stack = (void *)stack_it;
+
+		return 0;
+	}
+}